What is a key characteristic of a series circuit?

A key characteristic of a series circuit is that it provides a single path for current flow. In a series circuit, all components are connected end-to-end in a single loop, meaning that the electricity has only one way to travel through the circuit. If one component fails or is removed, the entire circuit is interrupted, which stops the flow of current.

This arrangement affects how voltage and current behave throughout the circuit. The total voltage in the circuit is divided among the components, and the same current flows through each component because there are no alternative paths for it to take. This is fundamentally different from a parallel circuit, where multiple paths allow current to flow even if one path is broken.

The other aspects mentioned, such as variable voltage inputs, high resistance, or having multiple paths for current flow, do not accurately describe the nature of a series circuit. In fact, the presence of multiple paths for current flow is specific to parallel circuits, while variable voltage inputs and high resistance can describe different types of circuits or configurations but do not specifically define a series circuit.